Benefit: When you activate your Arcane Strike feat, you can expend an unused enchantment spell that you have prepared or a spell slot of a level in which you know at least one enchantment spell (for spontaneous casters). If you do, any foe struck by one of your arcane strike-imbued attacks has a 50% chance to lose any action that they attempt, +5% per level of the enchantment spell expended, until your arcane strike ability ends on your next turn.